A Test of Faith
by Velkyn Karma
Summary: There's a reason every angel in the Bible starts its introduction with "Do not be afraid." On occasion it pays to remember that...even if one is your friend. The brothers are in over their heads, and Castiel resorts to drastic measures to help them. S6, set between "Like a Virgin" and "The French Mistake." Gen, no shipping.


**Test of Faith**

A fanfiction by Velkyn Karma

**Summary:** There's a reason every angel in the Bible starts its introduction with "Do not be afraid." On occasion it pays to remember that...even if one is your friend. S6, set between "Like a Virgin" and "The French Mistake." Gen, no shipping.

**Note:** This just sort of happened. I hadn't intended to write it, but then I thought, "what would happen if Cas had to possess one of the brothers?" and then all of a sudden, fic! Also written because, as much as I love funny/confused Castiel, it sometimes bewilders me that he goes from a powerful, scary being in his own right to comedy fodder, or that he lets the brothers push him around as much as he does. So I wanted to explore that a little.

**Warnings:** Swearing, and some descriptions of blood and gore. Spoiler warnings up to "The French Mistake" to be safe.

**Disclaimer:** I do not own, or pretend to own, _Supernatural_ or any of its subsequent characters, plots or other ideas. That right belongs to Warner Brothers and associated parties.

* * *

The first thing Dean is aware of is pain—mind-searing, atom-deep levels of pain that shred at the senses so violently they short out from the overbearing sensation of it all. It's the kind of pain he hasn't felt since he was stretched out on the rack in Hell itself.

The second thing Dean is aware of is surprise. Because the pain smashes through his memories like an eighteen wheeler through a china shop, but he's pretty friggin' sure he was in the middle of something, and yet he can't seem to grasp why he can't remember how he got here to begin with.

The pain doesn't recede—if anything it gets sharper and more defined. But Dean's the unfortunate bastard experienced in dealing with all kinds of agony, and manages to wrestle with it long enough to get back a few more bits and pieces.

He regains enough awareness to understand he's on his side on something cold and hard and rough—concrete, he thinks. He can hear muffled noises distantly that he thinks might be speech, but it's too hard to focus on the words. There's something slick and wet in his hands, which he realizes are cupped against his stomach after several long moments of confusion. Whatever it is feels familiar in a way that makes him feel nauseated and ashamed and afraid, but he can't quite put his figurative finger on what exactly his literal fingers are touching.

He can't see—he's sure his eyes are open, but his vision is black other than the red hot sparks that burst in time with his spikes of agony, enough for his brain to pull the plug on sight in favor of other more important things. But another explosion of red-hot pain against his darkened vision recedes long enough to leave him with the last thing he remembers seeing dancing in front of his currently sightless eyes: Sam, watching him in horror and screaming his name before going down under a swarm of half a dozen black-eyed figures.

The memory is the jolt Dean needs to start remembering more, collecting pieces and fitting them together. The weird mishaps in the town. His and Sam's guess that a Weapon of Heaven hidden somewhere nearby. Cas' immediate response to his prayer and his urgency to find the artifact. Tracking it down—in the hands of a dozen desperate, outcast, and very vengeful Lucifer-supporting demons, none of whom were fans of the Winchesters.

Not even a dozen demons would have stood a chance against Cas, not when he was at full power and determined as hell to recover the artifact. Dean remembers thinking they had it in the bag—until they discovered what the statuette did.

Specifically, casting out anything possessing a human being.

Handy little thing to have, Dean remembers thinking—would make exorcisms easy as Hell, bad pun fully intended. No wonder God or one of his angel lackeys would be willing to hand out something as strong as that in ye olden days, and no wonder both sides of Heaven were anxious to get it back.

Pity it worked on more than just demons.

Dean recalls vividly the sight of the artifact flashing, and of Cas' eyes rolling as he drops to the ground. The body of his vessel, Jimmy Novak, sprawls on the concrete and stares sightlessly. Dean's not even sure if the actual guy is still in there anymore and just too worn down from the constant presence of an angel to move, or if his soul took off ages ago during one of the times Cas has been torn apart. Hell, he's not even sure if the body's even breathing or has a beating heart on its own, but either way, Castiel's out of the fight.

Leaving Sam and Dean against twelve pissed off demons with nothing but vengeance and hatred in their black eyes.

Dean can't remember much of the fight, but he knows they put up a hell of a good one. They always do. Twelve is a lot to put down with no chance to really prep, though, and only one demon-killing knife between the two brothers. The combat is mostly a blur in his head, even though Dean is starting to realize it only happened a few minutes ago. He does remember the one demon that gets up in his face, though—even wearing a new body and a new look, he knows that sickly, twisted grin enough to recognize another student of Alistair when he sees one. So the hot burst of pain that erupts through his stomach seconds later really comes as no surprise, nor does the expert, practiced twist of the knife in his gut as the demon giggles at him knowingly.

Dean realizes with a jolt back to the hear and now that the slick, familiar substance in his hands are his own insides, sliding slippery and wet through his fingers towards the concrete floor no matter how hard (weakly) he tries to hold them inside. He should have known sooner. How often had he buried his fingers in some poor sinner's stomach and strung out their intestines, all under Alistair's gleeful instruction? The nausea and the shame grow stronger, and with it the pain.

He's aware of a rushing noise in his ears, now, and sounds beyond it, though it's hard to focus clearly. He thinks he hears screaming—he thinks it's Sam's voice—he knows the tone even if he can't make out the words. His little brother screaming, no matter _what_ the words are, is enough to make him struggle to rise, insides on the outside or no. But there's no strength left in him, just searing agony that radiates out through his stomach and fills his whole being. He's not Dean Winchester anymore, he's just an entity of pure pain and only the tiniest shred of consciousness remaining.

The rushing in his ears grows stronger, more muffling, and even Sam's already far-away voice is smothered and replaced with a high pitched buzzing whine, like when a person goes temporarily deaf. So apparently his ears have decided to check out, too. Distantly Dean is aware that he's probably dying—again—although this time it's hard to say for sure. He's used to his deaths being more sudden than this. This is slow, torturous, and annoying—he needs to either get better or get a damn move on, not hover in the middle like this.

The buzzing noise grows still higher in pitch, more whining, more persistent. It's actually starting to hurt, which just fucking figures—Dean's obviously not suffering _enough_, bleeding out on a floor, gutted open like a fish, with his intestines slopping out through his hands, so naturally his head's got to torture him, too. He wants to cover his ears, but his fingers are a little tied up at the moment—almost literally, _hah,_ it'd be funny if it didn't hurt so fucking bad—so he settles for trying to curl tighter and suffering.

The pitch grows higher, needle-sharp, like it's stabbing straight into his brain. Dean wants to think he's never experienced this kind of agony before, except, now that he thinks about it, he feels like it's sort of familiar. He can't place from where, or when, although it feels like a while ago, but he feels like it's not new. Where has...where did he...when...what...

_DEAN._

The voice explodes in his head at the same time that the whining pitch _screeches_ through his brain, and for a moment the agony in his stomach is _nothing_ compared to the thing in his head. Dean knows pain, he knows it intimately. But this is a whole new level that digs right down into the core of his being, and he can't keep himself from letting out a strangled whimper, or jerking spasmodically in reaction.

_I'M SORRY,_ the voice says next, and Dean can feel that it is, _whatever_ it is, but it's still _too much too much too much_ and it feels like his head is tearing apart from the inside trying to hold it. It's a voice. A _voice._ And it's kicking his ass. From the _inside._

Dean groans, and curls tighter on himself, willing himself to just fucking die already so he can stop hurting.

_YOU CAN'T,_ the..._thing_ says, and the strength of it tears through Dean's mind and makes him want to claw his own brain out. _YOU WILL, BUT YOU CAN'T. SAM NEEDS US._

Sam. Right. The voice is agony but it's right. Sam needs him. Need to save Sam. Sam hurting. Sam attacked by Lucifer-loving freaks. Sam needs...he needs to..._Sam..._

But already what little focus Dean managed to regain from the shock of the voice slapping him into awareness again is fading, and he's fading with it.

_NO!_ The voice snaps. Dean gets an impression of authority and firmness and strength in the voice and it's _powerful,_ stronger than before. Overwhelming. Too much for him to handle. He wants to cringe away, crawl into the corner and cover his head with his hands and hide, because it's so strong and he knows he screwed up somehow and it's _angry_ and he's so tired and confused and he doesn't want that. He feels like he's four again, and John Winchester's caught him stealing the last cookie from the cookie jar, and is giving him that disappointed-angry look of reprimand that makes him want to wilt.

He doesn't want the voice looking at him like that—and he knows damn well what he means. He knows the thing attached to the voice is watching him somehow.

And Dean is..._aware,_ vaguely, of a presence beyond the voice after a moment. He's not sure how—he's blind, practically deaf other than that continual screaming, whining noise in his ear, and slipping away into death, but he knows _something_ big is there. He can _feel_ it. And he _feels_ it seem to almost _sigh_ for a moment, and withdraw slightly, its presence becoming slightly less overbearing.

_I AM SORRY,_ it says again after a moment. It still hurts, digging into the depths of Dean's mind like an ice pick to his brain, but he also gets the impression of great care attached to each and every word. _I AM...TRYING TO...'LOWER THE VOLUME'...BUT IT IS DIFFICULT...AND WE DO NOT...HAVE...TIME._

Something about hearing an all-powerful, mind-tearing voice using the phrase 'lower the volume' tickles at Dean's memory, and he feels something bubble to the surface of his memories, although he's not sure if it's himself or the voice pulling it out of his head.

_"I warned her not to spy on my true form. It can be...overwhelming to humans. And so can my real voice...but you already knew that."_

_"You mean the gas station and the motel. That was you _talking?_ Buddy, next time, lower the volume."_

Dean's mind is hazy, but he manages to put two and two together after a moment, and slurs slowly, _"Cas?"_

Actually, in retrospect he's not sure that he spoke out loud at all. He's not sure he can, at this point—he can barely feel his body as it is. He wonders if he just thought the name in his head. He wonders if he's going crazy. He wonders, if he isn't, if Cas even heard him.

_I CAN HEAR YOU,_ the voice—_Castiel_—reassures. It's like thunder ricocheting around in Dean's head, and he lets out a reactionary keen of pain somewhere in the back of his throat.

He can _feel_ Castiel's frustration, distantly, which makes his skin crawl, because it feels so much more dangerous and potentially _literally_ earth shattering when he's a too-immense-to-comprehend presence and a teeth-jarring voice in his head. And seconds later he can _feel_ Castiel's urgency as the angel says, _THERE IS...NO TIME, DEAN. IT TOOK...TOO LONG TO...FIND MY WAY...BACK...AS IT IS. I CANNOT...TAKE MY VESSEL...BACK UNTIL...THE ARTIFACT'S SPELL...FADES. LET ME...TAKE OVER._

Dean balks at that—not just at the pain from the agonizingly long string of words, but at the half-request, half-order buried in them. _"No!"_ he snaps on impulse—out loud or in his head, he's not sure. Where the Hell does Cas get off, asking something like that anyway—

_DEAN,_ the voice says, and again Dean_ feels_ that frightening sense of overbearing frustration, _THERE IS NO T—_

_"No!"_ Dean hisses out-loud-in-his-head again, with what little strength he has left. _"No. No way. No pos...posse...no. No angels. No Michael. Team Free Will. No—"_

_I AM...NOT MICHAEL. DEAN._ The voice is insistent._ YOU ARE **DYING.**_

_"No."_

_SAM WILL ALSO DIE._

That gives him pause. He doesn't want Sam to die. Sam needs help. But they'd resisted before, refused to bow to Michael or Lucifer even when Zachariah was torturing them and threatening them. Sam wouldn't want him to give in now, not after everything they both went through to stay themselves and resist. And Dean never responds positively to threats, anyway. _"N..no. Save him...other way. No."_

_DEAN._ Castiel sounds even more insistent now, urgent, and it sends spikes of new agony through Dean's mind. _I AM NOT...THREATENING...YOU OR SAM. I AM...TRYING TO...SAVE YOU. BUT I...CANNOT...WITHOUT A...VESSEL._

_"Jimmy..."_

_IS BLOCKED...TO ME. THE ARTIFACT. IT WILL...FADE. NOT...IN TIME._ Cas' mind-shredding voice turns almost pleading, and the high-pitched whine lowers a few notes._ I SWEAR...DEAN. I WILL...RELEASE YOU...AS SOON AS...MY TRUE VESSEL...IS FREE. YOU...ARE...FRIEND. LET ME...HELP...YOU...SAM._

Dean hesitates a moment longer. It's _his_ free will, and _his_ body, and the thought of letting anything else take over, even Cas, makes his skin crawl. But his head is swimming, and he knows he's dying, and _Sam_...those demons are Lucifer's, they won't go as quickly with Sam as they did with him, they'll be livid because their master was locked away so quickly and they'll take it out on the one responsible. There's no time, _no time,_ and Cas...

Castiel is a friend. He stuck by them against Heaven itself when the Apocalypse came, and he hasn't abandoned them even now after the fact, even if he has been a little more distant than usual. If he has to trust anyone in an hour of need...well, there are worse choices than Castiel.

_"You swear?"_ Dean hears-but-not-really himself say.

_I SO SWEAR,_ Cas' voice answers solemnly. Even through its power Dean could swear he can hear a note of relief.

_"O...okay,"_ Dean says-thinks. _"Then...yes..."_

Dean had thought the pain of his gutted stomach was bad, and the pain of Castiel's true voice even worse, but he had been wrong in assume that was the worst it could get. _This_ was infinitely worse. He'd seen a lot of people possessed in he past, but he'd never actually been possessed by anything before—Sam was usually the one with other entities crawling around in his head. Dean had spent a year running from an angel hellbent (hah) on using him like a weapon, but he'd been fortunate enough to avoid Michael's possession entirely, even if he'd cut it close a few times. So he has no idea what to expect—but it certainly hadn't been _this._

It burns from the inside, consuming, powerful, _brilliant_, but it's nothing like roasting in hellfire—Dean knows that from experience, and isn't sure which one he prefers. This isn't roaring flames and malevolent intent, fire and brimstone and hate—this is blinding brilliance, absolute purity and law and order, serenity and steel and liquid sunlight, the very essence of guardianship and justice and devotion to God's will, and it's too fucking much to fit underneath Dean's skin. Castiel is more than just powerful—he _is_ power, absolute and overwhelming.

Dean has always thought of angels as arrogant, pretentious dicks, always assuming they're better than humans, always underestimating them, always deciding things for them like they're animals that can't be trusted to make decisions on their own. He's always wondered where the hell they got off, treating humans like less than dirt.

Now he thinks maybe he's starting to get it.

Castiel's presence on his mind is immense, an enormous pressure that burns from the inside, an intense brilliance that is just _too much._ It _hurts_, more than just his body—it burns at his mind, at his soul, at his sanity. Jimmy Novak had described it as being 'chained to a comet,' and Dean's starting to think the man had been putting it lightly. He gets now why the archangel's vessels are left drooling, decomposing messes when they're done with. He's afraid to even _try_ mentally glancing in the direction of Cas' true form; staring directly into the sun would probably be a safer alternative than that. He's suddenly overwhelmingly aware that Cas could crush his soul into powder with the barest exertion of effort, and he can barely think or focus due to the blindingly powerful essence of pure power and creation currently residing in him. He feels infinitesimally small, suddenly, even in his own body.

He doesn't like it. He immediately hates the sensation of being so small, so vulnerable, so utterly and unquestionably helpless. Dean has _never_ liked anyone rubbing in his face just how weak he is. So, daunting as it sounds, impossible as the task might be, he fights instinctively, automatically, on pure principle and fueled by pure stubbornness.

He may as well have thrown a pebble at a mountain, for all the good it does. Dean is no slouch and his willpower is second to none amongst humans, but Castiel's will is utterly unmoving, a wall of unrelenting force that Dean scratches at uselessly. He feels the first feelings of panic flicker through his already weak, exhausted, dying mind. And deeper still, he wonders in awe how on earth Sam managed to break _Lucifer's_ will, for surely the devil himself was infinitely more powerful then Castiel even on a bad day.

_DEAN,_ he hears Castiel's voice, and this time it hurts...less, actually. Dean has the strange and bewildering sensation that the angel is borrowing Dean's own thoughts and emotions before he even generates them, using the things inside his head to communicate back with him, shield him from his true voice. _BE CALM._

Easy for _him_ to say. Dean feels like he's been crushed into a tiny corner of his own mind and the angel's massive presence is taking up all the space in his head. He feels claustrophobic in his own _brain_, he can't breathe, he has no control, he can't do anything, _he can't do anything to save Sam—_

_DEAN,_ the voice repeats, insistent, but also with a great deal of...restraint? Patience? Dean's not sure, exactly. _BE CALM. STOP FIGHTING ME._

_"I can't—"_

_YOU MUST. YOU HAVE TO TRUST ME. YOU WERE CREATED AS A VESSEL FOR_ MICHAEL, _DEAN. YOUR BLOODLINE IS NOT ASSOCIATED WITH ME AND MINE, AND WHILE YOU ARE STRONG ENOUGH TO HOUSE OTHER ANGELS IT IS ONLY WITH DIFFICULTY THAT I CAN MAINTAIN POSSESSION. AN ARCHANGEL CAN HAVE PERFECT CONTROL, BUT LESSER ANGELS REQUIRE_ FAITH _FROM THEIR VESSELS. WE CANNOT AFFORD TO FIGHT THEM CONSTANTLY._

Dean vaguely remembers Jimmy's story, that one time he'd been separated from Castiel—the way he described multiple tests of faith, to display his complete trust in a nameless, faceless being claiming it was an angel before Castiel would even bother to possess him. It seemed stupid, really, but then, Dean's never really been one for all that 'faith' crap. Hell, Cas told him that first thing, the moment they met.

_I WILL NOT HARM YOU OR LET HARM COME TO YOU, OR TO SAM,_ Castiel's voice adds, almost reassuringly.

Something in the way he says it strikes Dean with a sudden memory of old—one in which John Winchester repeatedly assured a much younger, tinier Sam that he didn't have to worry about any monsters when he went to bed, because Dad would definitely get them if they showed their faces. Sammy had been too young to know about the family business, and young enough to keep asking with childish worry. But no matter how many times he repeated the question and how exasperated their Dad clearly got with each repetition, he always reassured Sammy with as much patience and restraint as he could manage.

And Dean gets that same impression now, from Castiel. That the angel is an immense and ancient and powerful being, far stronger than he'd realized, one that could easily sweep him aside or be irritated with him for his humanity and ignorance, and yet is still taking the time to reassure the thing so much smaller than him anyway.

Dean's given the angel a hell of a lot of crap in the past, and he knows it. He's often been frustrated with Cas' distant mannerisms, mocked him relentlessly for his lack of understanding about humans, and chewed him out more than once on some of his decisions. He's had the balls to order the angel around and tell him exactly what he thinks to his face and expected the angel to obey, and he's always thought of them as equals. And for the first time he's starting to realize it's actually been a hell of a lot like a tiny yippy terrier ordering a dinosaur around, and the dinosaur—fully able to crush the obnoxious little shit with a single claw—bemusedly plays along and deals with it instead, out of no other obligation than friendship.

It's a bewildering and kind of humbling realization to come to. Dean's not entirely sure he likes it. He _definitely_ doesn't like the vague hint of amusement he can feel from the overbearing presence of the being known as Castiel, currently taking up residence in his headspace, the moment the angel catches his thoughts.

_"Shut up, Cas,"_ he thinks. Yippy terrier, at it again. _"Fine. I trust you. Save Sam already."_

_OF COURSE._

It's one of the more difficult things he's done, but Dean forces himself to calm down, to stop vying for control against the powerful presence in his head, to try and back off as much as he can when he can't go that far at all. To his surprise, he finds that as soon as he does, Castiel's presence seems...less overbearing. It doesn't diminish, but it does become less claustrophobic, and he finds the panic at being trapped in his own head lessens. The intensity and brilliance and burning lessen next, until Dean feels almost comfortably warm and oddly safe, even floating in the confines of his mind.

_I AM ABLE TO SHIELD YOU FROM MY OWN PRESENCE BETTER, NOW THAT YOU ARE NO LONGER FIGHTING ME FOR CONTROL,_ Castiel explains unnecessarily.

_"Less wasting time, more burning those bastards,"_ Dean snaps back automatically, and fights himself to keep from fighting Cas automatically. _"Sam's dying here!"_

_YOU ARE THE ONE DYING,_ Castiel corrects with his usual frankness, _THOUGH I WILL REMEDY THAT SHORTLY. AND THIS IS THE LANDSCAPE OF THE MIND. BARE SECONDS HAVE PASSED SINCE I ASSUMED CONTROL._

Dean finds that hard to believe, but before he can comment on it further he's distracted by one of the most surreal sensations he's ever experienced, because he's moving—but he isn't—and he's seeing—but he isn't doing that, either. It feels almost like he's watching an old memory in his head, except he knows he's never done anything like this before, that it's happening _right now_, even if it feels disconnected.

He's distantly aware of his body standing, pushing itself up from the slick blood and cold concrete, one hand still pressed to his stomach to keep his insides relatively in place. He's aware of regaining his feet and gazing around, searching for his opponents, for Sam. He can hear the sounds of laughter, cruelty, and screaming—the last is his name, sounding panicked more than pained, and he know's it's Sam worrying about _him._ But it's all so far away, not as intense or as vivid as when it's really him and just him standing in his own skin, feeling all these things. He can barely smell or taste iron from the blood; he hardly feels the chill of the warehouse; he can feel the stickiness of his own blood as a vague sensation rather than cloying and wet. Even the voices feel muffled and distant, like he's wearing headphones, and his vision is blurred, like he's got sleep in his eyes still.

Again he feels the strange sensation of moving but not under his own power, and finds himself watching like a backseat driver as he steps towards the eight or nine demons in a gaggle around something huddled on the floor at the far side of the warehouse._ Sam_, he thinks, and instinctively tries to run forward to his brother, but his impulse is blocked by the iron will of the celestial being currently at the wheel in his head, and he bounces back in frustration. He considers fighting for control again anyway, and just barely remembers to not at the last minute. Faith, right. Trust and control. Can't afford to distract Cas right now, not when he's the only option they've got left.

Castiel-in-Dean's-body moves slowly and methodically, not at all with Dean's usual military, predatory stalk that Dad drove into him since he was a kid. Like he's got all the time in the damn world to make it ten feet. Sam could be _dying. "Pick up the friggin pace!"_ he snaps in his head, but Cas—although he most certainly hears him—doesn't listen.

Freakin' old as hell angels. Castiel's presence might be overbearing but Dean still finds it in him to be frustrated with his friend's methods. So that hasn't changed, at least.

Cas stops a few feet away, and Dean realizes now that the demons haven't noticed him. Sam, however, has—while desperately looking for his brother, to see if he was still alive, if he could still be saved. Sam's eyes widen in confusion and surprise and maybe a little fear, and distantly Dean realizes that he must look quite a sight right now—casually standing around with his guts hanging out like things are no big deal. No wonder he's alarmed. Dean wants to reassure him, but, well, he doesn't exactly have the ability to talk for himself right now.

But he does talk—or at least his body does, under Castiel's direction. "Sam," Dean hears his own voice order—in an authoritative, deeper than usual serious tone, not at all like how he usually speaks and sounding all kinds of unnatural, "Close your eyes!"

Dean spots the flicker of confusion in Sam's gaze, but his brother's not stupid—his eyes snap closed immediately, and he covers his face with his one working hand as well. The demons aren't nearly so smart, and whirl around in confusion, looking bewildered.

"I thought you killed him?"

"I did! I gutted him like a trout! He's gotta be—"

"How the fuck is he—"

Dean feels his free hand, the one not holding his stomach together, rise and aim open-palmed at the demons. The one on the far left's eyes widen in surprise as it figures it out, and it fumbles with the statuette artifact, screeching, "The angel is—"

That's as far as it gets, and also as much as Dean sees. He feels the iron will that is Castiel's being shift suddenly around him, and his ability to see out of his own eyes—poor and distant though it may be—goes completely black, and all he can hear is screaming. He fumbles in his head in a moment of panic, but Castiel's voice says, _BE CALM_, just like before, and it's enough reassurance for Dean to know he hasn't suddenly died or gotten his eyes burned out, at least.

When Cas gives him his vision back, the fight is over. Nine corpses lay sprawled out on the floor before him, all with their eyes burnt out and smoking, one still clutching the statuette that had put them through so much trouble. Dean feels his eyes turning to regard the artifact carefully, before glancing over to look at Sam.

_"Help him,"_ Dean half orders, half pleads immediately. Sam's been worse, but he hates seeing his little brother like this anyway, bruised and bleeding and with one arm that is almost certainly broken. There's several gashes from a knife on his arms and legs and at least one slice on his face, and that had all happened in a few bare minutes. Dean finds himself relieved that they—that Cas—was able to stop the demons when he did. He knows what Hell's capable of, especially Alistair's students, and he doesn't need to see that happening to Sammy, or risking breaking the Wall where he's sure even worse things are hidden.

Castiel seems to hesitate a fraction of a second, again glancing at the artifact, before nodding and standing over Sam. "It's over," he says, again using Dean's now too-deep voice in exactly the wrong way, and Sam lifts his hand from his eyes, glancing up at Dean-but-not-really.

He looks...wary. Alarmed. Not afraid, exactly, but Sam's smart and Dean knows it. Sam knows Dean's probably not in command right now, not after that light stunt. They don't have the best track record with angels, though, and Dean's sure Sam is already wondering who on Earth (or Heaven, for that matter) he might have said 'yes' to.

"Cas?" He finally ventures after a moment, still wary. Good guess, but then, Sam's always been ahead of the game that way.

"Yes," Castiel answers with Dean's voice. For Sam's benefit he adds, "My vessel is currently blocked by the artifact's power. Dean agreed to temporarily house me in order to save the both of you. He wishes for me to heal you now."

Sam grimaces, even as he stumbles wearily to his feet, favoring one leg. "Of course he would," he mutters under his breath, and Dean barely manages to hear it through the muffled partial senses he has access to. He glances in the direction of Dean's stomach before hastily looking away again, frowning and looking a little green. "His intestines are on the wrong side of his skin but he wants _me_ with the bumps and scrapes healed first."

_"Hey, it's not like I can die right now with an angel battery,"_ Dean snaps back on impulse, even if he can't actually get the words to Sam himself. _"May as well get you taken care of first."_

He can vaguely feel the immense being that is Castiel shift slightly in what he swears is amusement, or exasperation, or maybe both. Out loud (again using Dean's voice), Cas just says, "He will be fine as long as I am here to preserve him. He desires for you to be cared for first. You know your brother."

"Yeah," Sam murmurs again. He seems more at ease than he had been when Dean started making angel lightshows, but Dean can tell he's still slightly wary, Cas or no. Dean can't blame him—he's never liked it when Sam was possessed in the past either. Even if it's Cas, it's still unsettling to have your brother less than two feet from you and yet so far away. And Sam's last experience with angel possession ended up with him taking a nosedive into Hell, so he's got even more reason to be concerned.

But Dean doesn't like that Sam's head is clearly turning in that direction, based on the way he subtly shifts enough that he can make a grab for Cas should he decide to take off in Dean's body. Nor does he like the way Sam is again eyeing Dean's currently exposed innards with obvious concern, or the uncomfortable look in his eye that says he's thinking too deeply about it. Thoughts like that will lead straight into Hell, and Dean can't afford that, not when Sam's soul is so fresh out of it.

_"Don't let him keep poking the Wall,"_ Dean hisses to Castiel in his head. _"Heal him, move things along—something!"_

Cas obliges, with more than a little of that restraint and patience, and Dean realizes that once again the overbearing, soul-crushing presence of a powerful celestial being is conceding to the whims and orders of a tiny, insignificant dust speck of a human, entirely by its own choice. Dean's not sure what to think of that, but he doesn't really care, because Cas is already reaching out to take Sam's broken arm in his borrowed hands, still slick with Dean's own blood. Sam flinches—Dean's not sure if it's because of the blood or the pain of moving the arm—but a moment later relaxes as Castiel's healing abilities start to set in.

Then he frowns, and voices precisely what Dean is thinking in his head. "Isn't this usually instant for you?"

"Dean is not my true vessel," Castiel explains in Dean's voice—and hell it's weird, listening to himself refer to himself in the third person. "I must exercise great restraint and care in utilizing my power or risk destroying him by accident."

_"What?"_ Sam yelps in alarm, and Dean echoes him inside his head.

Castiel continues the much slower healing process—Dean can sort of feel distantly the angel's extension of his power, the force of creation embedded in him cycling out to circle through Sam's wounded arm and back again. Now that he thinks about it, though, that...flow of energy, he guesses...is a weak trickle, like it's trying to squeeze through a dam or something. A dam made by Cas, he realizes—the angel isn't letting much out at all.

He also appears to be considering something—probably how to dumb the explanation down for them—and after a moment says, "You recall that you and Dean were bred for very _specific_ angels."

_"Little hard to forget that,"_ Dean snaps impatiently, as Sam nods.

"Specific bloodlines, special humans, have unique connections to specific angels," Cas explains carefully. "Jimmy Novak is of the line closest connected to myself. This is how I may utilize my power to the fullest extent when possessing him. His bloodline is...tailor-made...to my specific abilities and power."

"But Dean isn't," Sam said slowly. "Or me."

"No. Dean was intended for an archangel. A being far more powerful than myself. That means he was...built...with a great degree of endurance, to be able to withstand the...pressure...of such a powerful being residing inside of him. This is how I, a weaker angel by comparison, am able to possess him at all. But otherwise it is a poor match—possible for a time, but at the expense of the vessel."

Sam swallows, and says after a moment, "Like Nick?"

_"Change the topic. Now,"_ Dean orders mentally. He doesn't like that look on Sam's face again—he's getting too close to things better left not thought about, and that overrides his concern for himself and the potential incoming nasty-looking decay in his future if Cas were to change his mind and stick around.

"Possibly," Castiel acknowledges, but adds quickly, "But it will hardly matter. I don't intend to stay long enough to cause such damage. Dean has enough endurance as a vessel to last quite some time before anything were to happen to him, as long as I do not overexert my abilities while residing in him. Healing will take longer, but—there." He releases Sam's arm, now good as new, and moves to the next of the younger Winchester's bruises.

For a time things pass like that. Castiel methodically tends to each and every one of Sam's injuries, and once he's finished and Dean is damn well sure of it, he moves on to his temporary vessel. Dean mentally shivers at the strange sensation of Castiel calmly gathering up all his innards and pushing them carefully back in, before placing his hand over the gaping, bleeding hole and beginning the healing cycle anew. Light blossoms underneath his hand, and this close Dean can feel the intensity and brilliance of the angel grow stronger, enough to make his soul shudder.

_SORRY,_ Dean hears Castiel apologize mentally, and the intensity backs off a little. _A MORE DIFFICULT INJURY. I ASSUMED—NO MATTER. THIS WILL TAKE TIME._

_"Whatever. Long as I'm not bleeding out and everything's where it's supposed to be."_

In the end it takes the better part of an hour, spent awkwardly with Dean appearing to stand still and peer into blank space, hand over his stomach as the injury gradually recedes, and Sam fidgeting awkwardly, unsure what to do now. Dean doesn't blame him, as the situation is all _kinds_ of awkward, although as usual Cas seems utterly oblivious to it.

Dean is kind of surprised at the effort Cas puts into healing him, though. Dean had always sort of assumed that Cas just touched an injury and _poof,_ all better. He realizes now, after sort of observing the angel at work from a distance in his own body, that it's way more complex than that. He's only getting a portion of it, but Castiel seems to have a stunningly complex comprehension of the human body down to nearly a molecular level, as he creates, rearranges, and even reverses time for each individual cell until everything is in the right place again. And normally he does it all _instantly_. That's more mind power than Dean cares to think about in any one individual.

He's kind of glad Cas is on their side. Like, _really_ glad, now that he's seeing the angel for what he is.

After a while Castiel finally withdraws his (Dean's) hand, flexing their now-bloodless fingers experimentally. The tear in Dean's stomach is gone, and Cas even fixed his shirt, which is great, since those things are a pain to keep replacing after hunts as it is. Dean prods mentally at the former injury since he can't do it physically, and after a moment thinks, _"Thanks, Cas."_

_OF COURSE._

_"What about you?"_ He mentally nods to the unmoving body of Jimmy Novak, who Sam has shifted to a more comfortable position but has otherwise remained still and nearly lifeless. _"Can you get back in yet?"_

_NOT YET. THE SPELL IS FADING, BUT NOT YET BROKEN._

Dean mentally sighs. _"Seriously? We gonna have to stand around here all night? This sucks."_ He wants to get the hell out of there already, have his body again, get his control back. _Definitely_ wants to make sure Sam is alright, after this whole mess, and not scratching at the wall too harshly after so many potential triggers here to maybe make things worse. Wants to grab a burger after a hard day's work (even if he actually doesn't feel remotely hungry right now, due to Cas' presence), and maybe get a few hours sleep at their usual crappy motel (though again, thanks to Cas, he's not tired right now).

Dean swears he can almost_ feel_ Cas doing that contemplating-frown thing he does, when he's trying to figure something out about humans that he doesn't quite get yet. Then the presence shifts again, and says, _PERHAPS I CAN—_

Dean jolts in surprise as all of his senses come rushing back to him suddenly. His vision instantly becomes sharper, his hearing more focused, scent and taste and touch more vivid. He feels the very faint edges of hunger and fatigue, but distantly, like they're not really important so much as a side effect. But mostly he feels dizzy and disoriented, and nearly crumples as he is thrown back into standing before he's ready and nearly forgets how.

Sam lunges forward hastily and catches him before he hits the concrete on his knees, and helps him stand again, one hand on his shoulder. "Cas? You okay?"

"Not Cas—me." Dean winces and massages his forehead carefully with the heel of one hand. He still feels that overwhelming sense of _pressure_ inside, and realizes Cas is still there, an enormous presence too massive and powerful for his brain to fully comprehend. But he's relinquished his control on Dean's body, and appears to be, for all intents and purposes, withdrawing as much as he can from Dean's mind while still hiding in it. It's a bit bewilderingly like an elephant trying to cram itself into a tiny bedroom closet so as not to get in the way, and that strength and presence is still giving him one hell of a mind-ache, but Dean'll give the angel points for trying.

Sam looks relieved, although a second later he's frowning and glancing back at he still body of Jimmy Novak. "Did he go back?"

"No. Still here," Dean says, forcing himself to stop rubbing his forehead. "Just hiding in the back. If you can call even being semi-possessed by an angel 'hiding.' Like a freakin' lighthouse beacon_ right_ behind my eyes."

_THIS IS NOT AS EASY AS IT APPEARS, YOU KNOW,_ Castiel's voice says from the back of his head. If he'd still been in his actual vessel when he said it, and more or less human, Dean's sure it would have come across as almost sulky. As it is, Cas' voice—even using Dean's own borrowed thoughts to communicate—is still so powerful and overbearing that he sounds more reprimanding and irritated than anything else. Dean has to fight the urge to start confessing his sins on impulse to make the agent of God stop looking in his direction all angry-like. Relatively speaking, anyway.

Sam, unaware of Cas' presence at all, winces in sympathy. "I know what you mean," he says in agreement. And he probably does—better, even. Cas was polite enough to back off, and try to protect Dean from the radiance a little. Dean's pretty sure Lucifer did no such thing, and wasn't he known for being extra shiny or something?

_THE MORNING STAR,_ Castiel says in idle agreement.

_"Hey! Stay out of my head,"_ Dean thinks back to him with a mental scowl. _"Or...my mind. Thoughts. Whatever. You know what I mean."_

_I DO, BUT THAT IS NOT AS EASY AS YOU THINK. I CAN HEAR YOUR PRAYERS FROM ACROSS THE WORLD AND IN OTHER PLANES OF THE AFTERLIFE, AND THAT IS IN ANOTHER VESSEL ENTIRELY. YOUR MIND IS CURRENTLY AN OPEN BOOK NOW THAT I RESIDE IN IT, HOWEVER TEMPORARILY._

Dean scowls mentally at him again, and immediately starts thinking about the most recent copy of _Busty Asian Beauties_ he'd gotten his hands on, as hard as he can. He can sense the celestial force in his head immediately backpedaling in what is most definitely awkward bewilderment. A moment later Cas' voice says in what Dean is pretty sure is sheepish compromise no matter how incomprehensibly powerful it is, _PERHAPS IT WOULD BE BEST IF I SIMPLY PRETENDED I HEARD NOTHING. AND NOT COMMENT ON IT._

_"I think that's the best plan you've had since you got here,"_ Dean agrees, and drops his thoughts to more church-appropriate levels.

Sam is shaking him, he realizes, and Dean snaps out of what he realizes has become a glazed sort of stare. "Sorry," Dean says. "Talking to Cas. _Man_ it's not as easy to multitask on that as I thought."

"What do we do now?" Sam asks, after giving him a concerned look for a moment. "Do we know how long this is gonna last?" He glances at Dean, and then over to Jimmy's prone body.

"Not sure. Cas says it's fading, but it's probably gonna be a while still," Dean says. "We don't know if these demons have any buddies, or who else knows about that thing." He gestures to one of Sam's coat pockets, where he stuck the statuette while waiting for Cas to finish healing Dean. "Figure we'd better hightail it. We run into more demons, Cas can handle those, but if more angels show up we might be in trouble."

"And we don't know how to use the artifact, so that wouldn't be any help," Sam agrees.

_FIGHTING RAPHAEL'S FOLLOWERS WOULD BE DIFFICULT WITHOUT MY PROPER VESSEL,_ Castiel adds from inside Dean's head. _IT WOULD BE BEST TO AVOID CONFRONTATIONS FOR NOW._

So they do. They cart Jimmy's body out to the Impala and lay it out in the backseat. Dean lets Cas take over again just long enough to grab their stuff from the motel across town, and flying is the weirdest experience yet. Dean's always _known_ Castiel comes with wings, but it's another thing entirely to feel them coming out his shoulder blades, and although they're too intense to look at directly he's pretty sure he catches sight of more than one pair out the corner of his eye. But it's fast, so it takes only a few minutes to snag their bags and zip back to the Impala.

They get the hell out of there before anyone else can come investigating. Cas slides into the back of Dean's head again as best he can, and quietly keeps to himself unless addressed. He's very good at perfect stillness and absolutely nothing, Dean discovers, presumably because he's ancient and also more or less timeless, which probably explains how he can stand on street corners for six hours at a time waiting for something to happen. He's still an enormous pressure on Dean's mind even so, enough to make him relent and allow Sam to drive, although he's also starting to adjust a little better to it than before. Sam seems concerned by this, since Dean usually needs to be having a _really_ bad day before he'll hand over the keys, but Dean waves him off and dedicates himself to keeping the conversation about pretty much anything but angel possession, literally Hellish injuries, and anything else that could scratch at Sam's Wall.

They drive aimlessly for several hours, not heading anywhere in particular—just trying to stay moving. In the end it's nearly midnight before the spell finally wears off completely. It's a good thing too, because Sam's starting to look pretty beat (Dean, no thanks to Cas, hasn't even thought once about sleep). Dean's just starting to suggest finding a motel to hole up in and mark up with as many warding sigils as possible when the celestial force in the back of his head suddenly stirs, for the first time in hours, and the pressure in his head immediately grows stronger. A moment later, Castiel's voice says,_ THE SPELL HAS FINALLY FALLEN FROM MY VESSEL. I MAY RETURN TO IT._

"Pull over," Dean says immediately. "Cas says he can go back." Sam, looking relieved for probably more than one reason, obeys, pulling the car over on the side of the highway.

In the end it's sort of anticlimactic. Dean half expects flashes of light, rumbles of thunder, sparks flying...the works. Instead, the heavy pressure of a being far too immense for Dean to properly comprehend is in his head one minute, and the next second it's just gone. Dean sways slightly in his seat as sudden exhaustion and hunger—all the things Cas' presence kept at bay—suddenly return, but compared to the overwhelming headache-inducing force in his head those things are easy to deal with.

He glances over his shoulder into the back seat just in time to see Jimmy's eye snap open. The body abruptly sits up, and Castiel, once again properly in his own vessel, turns to look at them.

"Much better," he says, flexing a hand experimentally. After listening to the angel's real voice for a few hours now, Jimmy's borrowed one, completely devoid of power and utterly ordinary, sounds almost strange. "Even an archangel's vessel is a poor substitute for a proper match."

"Hey!" Dean growls, feeling inexplicably insulted somehow. Sam looks like he's not sure if he should be equally insulted, worried, or start laughing.

"No disrespect meant," Castiel says. Then he leans forward, reaching his hand out expectantly over the bench seat. "I must place the artifact with the rest of the Weapons of Heaven we have recovered so far. We have already delayed too much as it is."

Sam wordlessly reaches into his pocket and slaps the statuette into Castiel's hand. The angel's fingers curl around it protectively immediately, and he shifts slightly. Even though Dean can no longer _feel_ that essence of pure power anymore, with it safely hidden in a vessel, he knows the angel's about to take off on them again, and who knows when he'll be back, with the way things have been going lately?

"Cas!" he barks, before the angel actually vanishes. Castiel turns to look at him patiently, and Dean adds, "Don't go thinking that 'yes' is an invitation to pop in whenever, got it? It's a one-time deal."

"Even if you are dying again?" Castiel asks, cocking his head just slightly the way he does when he doesn't quite get human mannerisms and is attempting to puzzle it out.

"Even if. You ask me again if that happens. It's the same as the personal space thing, only _more._ Got it?"

Castiel seems to be considering this, which doesn't surprise Dean any since he forgets the 'personal bubble' rule so often. Angels, man. All that power and wisdom and pure force to their name, but even the simplest of concepts seems beyond them. After a moment, though, Cas nods seriously. "I will not abuse your agreement."

"Good." That's a relief, at least. Even in an emergency situation with his and Sam's lives on the line, being possessed had not been a pleasant or welcome experience. It's not something he wants to repeat, least of all suddenly and without his approval.

After a moment he adds, "And, ah...thanks."

It's intended as more than a_ thanks for saving our asses again,_ although he doesn't say it out loud. It's also _thanks for actually bothering to take care of your vessel instead of letting it rot_ and _thanks for not being a douchebag about staying in control the whole time_ and, most importantly, _thanks for not betraying my trust_, because Dean never did 'faith' well and it had taken a hell of a lot out of him, more than he liked to admit. He's not sure if Cas will actually get the message in full, but he thinks the angel does, because Cas stares at him for a long moment before nodding once, and then he's gone.

Dean blinks for a moment at the now empty back seat, and glances at Sam, who's glancing right back at him. After a moment, Dean shakes his head, and says, "Cas and the thing're gone—I think we're good to find someplace for the night. I don't know about you, but I could sleep for a week."

Sam nods tiredly in agreement. "Amen to that," he mutters under his breath. Dean can't help but snort at his word choice, before thinking back to the day's events, rubbing a hand idly over his stomach that mere hours ago had been a gaping, open mess.

Cas had really saved their asses today. What with getting cut off from Heaven and all his human sympathizing, Dean had sort of forgotten that when Castiel wanted to, he could really cut loose. He was definitely more than a glorified band-aid, and Dean had never realized how truly _powerful_ he was. He should probably cut the guy a little slack in the future, snap at him a little less, appreciate how freakin' lucky they were to have an on-call angel not just as an ally but as a_ friend._

Well. Maybe not _too_ much. After all, how often did _anybody_ get to make fun of an angel trying to figure out cell phones?

* * *

Castiel gets "de-powered" or turned comedic so often I think everyone occasionally forgets how powerful he really is! Or that he is an entity outside of a human vessel since he's mostly associated with Jimmy. I always love those moments in series when he reminds us of that, but there just aren't enough of them.

~VelkynKarma


End file.
